Remote dog training devices that include hand-held remote-control radio transmitters and light-weight radio receivers are known. In fact, there are a number of publications that describe training animals using electric shock collars. For example, Understanding Electronic Dog-Training, by Dr. Daniel F. Tortora (1982), describes methods for using shock collars for training animals. Moreover, some of these inventions have been patented. For example, U.S. Pat. No. 4,335,682 describes a remotely controlled device that is worn by a dog. The device produces stimuli, such as an aversive electrical stimulus, that is followed by a sound or other second stimulus to condition the animal. This helps train the animal for its own safety, or perhaps to provide a relaxation response. Other stimuli also may be produced just prior to the onset of the aversive electrical stimulation. This becomes a conditioned warning stimulus to the animal.
U.S. Pat. No. 4,471,954 states that it is essential that training collars reliably and consistently apply an intended degree of stimulus to the animal. This is complicated by the fact that dogs have various coat and skin thicknesses. Also, certain environmental factors may change the conductivity of the animal's coat or skin, and hence the intensity of the signal perceived by the animal wearing the collar. One example of such an environmental factor is humidity or rain. If the animal's fur is wet, its ability to conduct electricity increases. As a result, stimulating the animal at an early stage in a field training exercise may be less intensely received by the animal compared to the intensity of the stimulus received after the dog's coat is moistened.
Another animal training apparatus is described in U.S. Pat. No. 4,802,482. This patent also concerns solving the problem of providing optimum stimulus levels to the dog for particular training conditions. If the stimulus is too intense, it may have negative effects on the animal. On the other hand, the stimulus must be sufficiently intense to achieve the desired training or control desired.
While a number of inventions are known for remotely stimulating dogs and other animals for training purposes, it still is difficult to track such animals if they are off-leash and moving far afield. In fact, dogs often are lost during training exercises or competitions as they wander too far from the owner or trainer. In this situation, not only may a prize animal be lost but so would the expensive training collar being worn by the animal.